This invention relates to monitoring the fetal heart cycle.
A tachometer useful for deriving a fetal heart rate from an electrical signal impressed with the fetal heart cycle is disclosed in U.S. Pat. No. 3,811,428.
At times it is desirable to use such a tachometer with an input signal derived from the fetal heart cycle through a mechanical energy transducer, such as an ultrasonic or phonocardiographic pickup. Problems in obtaining good quality inputs from such pickups have been experienced.